Massachusetts Alzheimer?s Disease Research Center: Biomarker Core The Biomarker Core of the Massachusetts Alzheimer?s Disease Research Center (MADRC) supports and performs biofluid biomarker research to contribute to our understanding heterogeneity in Alzheimer?s disease and Alzheimer?s disease related disorders (AD/ADRD) and to accelerate progress towards a cure. We carry out core functions, marshaling resources to enhance the research mission through Aim 1's collection, curation and distribution activities for blood and cerebrospinal fluids (CSF) for MADRC, local and national research and Aim 2's standardized performance of essential molecular diagnostic assays of amyloid- b42 and tau to contribute to biological classification of AD/ADRDs in the MADRC Research Cohort and other samples. We develop and implement new strategies and accelerate progress towards a cure in Aim 3 and 4's refinement and validation of novel ELISA, Simoa, and MS assays targeting multiple pathophysiological pathways in blood and CSF, and in Aim 5's express focus on understanding those assays' utility for clinical and clinical trials settings. These novel approaches are piloted in the MADRC collections of blood and CSF spanning diverse AD/ADRD diagnoses, stages of disease, prognosis, demography (including sex as a biological variable), risk factors, heterogeneous pathophysiological drivers, and treatment. Successful pilot work and biofluid sample resources are then leveraged to facilitate larger focused research projects in and outside of the MADRC community. We build the future in Aim 6 by providing expertise, education, training and laboratory resources to faculty, trainees and students for best practices in biofluids biomarker research, and in Aim 7 by providing education to researchers, clinicians and the public on the advances, utility and responsible interpretation of biomarker data in ADRD research and ultimately how biomarkers can be used in caring for people with AD/ADRD.